This is not an attempt to clean up the various issues with the pthread
logic, instead just moving the pthread specific logic out of FEXCore in
to FEXLoader.
FEXCore needs to know how to create threads in an agnostic way. Which is
why we obfuscate the details with this inteface.
Initially this was implemented with the pthread handlers in FEXCore and
expected eventually for those to get moved to the frontend. This is the
time when it has been moved.
This is the first step towards compiling with llvm-mingw.
Still a long way to go.
Every time we are calling a function in `FEXCore::Allocator::` this is a
pointer indirection. Which means on x86 it is always a `call [rdi]` and
on AArch64 it is a `ldr x17, [x0]; blr x17;`.
Instead of doing this, use inline functions in the header that call the
correct allocation function directly. This function gets inlined and is
no longer an indirect call.
When compiling with jemalloc, we forward declare the jemalloc function
definitions so we don't have to pull in the entire jemalloc interface in
to the public header definitions.
This is done by consuming a single page at the end of the current sbrk
memory region. Then consuming any remaining bytes that could have
potentially ended up in it.
This ensures that glibc won't be able to return 64-bit pointers to
32-bit thunks once the remaining work is in place.
Optimize `FileLoad` by not using fstream.
For some reason fstream is just really bad.
Switching over to raw pread cuts the amount of time it takes to read
files by a quarter of CPU time.
If we have a fixed file to read, we can read it in three syscalls.
fstream is...weirdly slow in the other implementation.
Theoretically in the future this can be improved to a single syscall if
the `readfile` syscall ends up in upstream Linux.
- Some minor cleanups in the VMARegion struct type.
- Switches over to using the FlexBitSet range scanning, based off this
implementation.
- Move memory region allocation to its own function instead of
constructor
- This will be used by a new constructor later for 48-bit host-side
allocations
- Minor optimization to keep track of Munmap.
- We were burning a bunch of time on backward scanning for free
regions even though we never did a munmap to free anything.
- Now only do backward scanning if a munmap occured.
- Saves a bunch of CPU time
Ryan Houdek